Hydro 35

All Other Wound Healing Agents
Humectants
Keratolytic Agents
Osmotic Agents for Cerebral Edema
Other Medical Foods

For storage information, see the specific product information within the how Supplied section.

Powder for Oral Solution
Mix each 15 g packet with 90 to 120 mL of water or juice.
May be administered orally or via nasogastric or gastric tube.

To enhance the moisturizing effects of urea, apply after washing or bathing while the skin is still moist.

hypokalemia / Delayed / Incidence not known
hypernatremia / Delayed / Incidence not known

skin irritation / Early / Incidence not known
vomiting / Early / Incidence not known
headache / Early / Incidence not known
diarrhea / Early / Incidence not known

Aluvea, BP-50% Urea, BP-K50, Carmol, CEM-Urea, Cerovel, DermacinRx Urea, DERMASORB XM Complete, Epimide-50, Gordons Urea, Hydro 35, Hydro 40, Keralac, Keralac Nailstik, Keratol, Kerol, Latrix, Nutraplus, RE Urea 40, RE Urea 50, Rea Lo, Remeven, RYNODERM, U-Kera, Ultra Mide 25, Ultralytic-2, Umecta, URALISS, Uramaxin, Uramaxin GT, URE-K, Ure-Na, Urea, Ureacin, Ureacin-10, Ureacin-20, Uredeb, Uremez-40, Utopic, Vanamide, X-VIATE, Xurea

Rx, OTC

Also known as carbamide
Available as topical and oral formulations
Used topically for xerosis or destruction/dissolution of dystrophic nails due to onychomycosis and systemically for treatment of hyponatremia, particularly due to SIADH

Apply to the affected nail tissue twice daily. Protect the surrounding skin. The treated area may be covered with an adhesive bandage or gauze. The finger of a plastic or vinyl glove may be cut and slipped over the bandaged area. Keep dry and occlusive for 3 to 7 days.

Apply the 40% to 50% preparation twice daily to affected areas. If desired, cover with adhesive bandage or gauze, secured with adhesive tape.

Rub in gently the 10% to 45% preparation twice daily to affected skin.

Apply the 40% to 50% preparation twice daily to the affected area and rub in completely.

15 to 60 g/day PO in 1 to 4 divided doses is the usual dose. Doses as high as 120 g/day PO in 4 divided doses or 180 g/day PO in 6 divided doses have been used. The dosage can be titrated in 15 g/day increments at weekly intervals as necessary to achieve normal serum sodium. Clinical practice guidelines recommend urea as second line therapy (following fluid restriction) for moderate to severe hyponatremia in patients with SIADH.

Data are very limited in pediatric patients; however, initial doses of 0.1 to 0.7 g/kg/day PO, titrated to a maximum dose of 1 to 2 g/kg/day PO in 3 to 4 divided doses have been used.

Specific guidelines for dosage adjustments in renal impairment are not available. It appears that no dosage adjustments are needed for topically administered products.

Specific guidelines for dosage adjustments in hepatic impairment are not available. It appears that no dosage adjustments are needed for topically administered products.

Acetazolamide: (Moderate) Carbonic anhydrase inhibitors promote electrolyte excretion including hydrogen ions, sodium, and potassium. They can enhance the sodium depleting effects of other diuretics when used concurrently. Pre-existing hypokalemia and hyperuricemia can also be potentiated by carbonic anhydrase inhibitors. Monitor serum potassium to determine the need for potassium supplementation and alteration in drug therapy.
Aminoglycosides: (Moderate) The risk of ototoxicity or nephrotoxicity secondary to aminoglycosides may be increased by the addition of concomitant therapies with similar side effects, including urea. In addition, urea may alter the serum and tissue concentrations of tobramycin, thereby, increasing the risk for aminoglycoside toxicities. If possible, avoid concurrent use. If these drugs must be used together, it would be prudent to monitor renal function, serum electrolytes, and serum aminoglycoside concentrations. Audiologic monitoring may be advisable during high dose therapy or therapy of long duration, when hearing loss is suspected, or in selected risk groups (e.g., neonates).
Carbonic anhydrase inhibitors: (Moderate) Carbonic anhydrase inhibitors promote electrolyte excretion including hydrogen ions, sodium, and potassium. They can enhance the sodium depleting effects of other diuretics when used concurrently. Pre-existing hypokalemia and hyperuricemia can also be potentiated by carbonic anhydrase inhibitors. Monitor serum potassium to determine the need for potassium supplementation and alteration in drug therapy.
Desmopressin: (Minor) The manufacturer notes that the antidiuretic effect of desmopressin can be enhanced by the concomitant administration of urea. Dosage adjustments of desmopressin may be necessary to maintain proper sodium and water balance.
Epoprostenol: (Moderate) Further reductions in blood pressure may occur when epoprostenol is administered with diuretics.
Iloprost: (Moderate) Further reductions in blood pressure may occur when inhaled iloprost is administered to patients receiving other antihypertensive agents.
Lithium: (Major) Diuretics that act at the proximal tubule (like injectable Urea) will increase urinary lithium excretion by interfering with the primary site of lithium tubular reabsorption. Patients receiving these agents concomitantly should be monitored very closely to ensure that the desired clinical response to lithium continues to occur. Also carefully monitor renal function during combined use. Monitor serum lithium levels closely and adjust the lithium dosage if necessary.
Methazolamide: (Moderate) Carbonic anhydrase inhibitors promote electrolyte excretion including hydrogen ions, sodium, and potassium. They can enhance the sodium depleting effects of other diuretics when used concurrently. Pre-existing hypokalemia and hyperuricemia can also be potentiated by carbonic anhydrase inhibitors. Monitor serum potassium to determine the need for potassium supplementation and alteration in drug therapy.
Nifedipine: (Moderate) Nifedipine can have additive hypotensive effects with other antihypertensive agents (including diuretics). This additive effect can be desirable, but the patient should be monitored carefully and the dosage should be adjusted based on clinical response.
Nonsteroidal antiinflammatory drugs: (Moderate) Nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the natriuretic effect of diuretics in some patients. NSAIDS have been associated with an inhibition of prostaglandin synthesis, which may result in reduced renal blood flow leading to renal insufficiency and increases in blood pressure that are often accompanied by peripheral edema and weight gain. Patients taking diuretics and NSAIDS concurrently are at higher risk of developing renal insufficiency. If an NSAID and a diuretic are used concurrently, carefully monitor the patient for signs and symptoms of decreased renal function and diuretic efficacy.
Octreotide: (Moderate) Patients receiving diuretics or other agents to control fluid and electrolyte balance may require dosage adjustments while receiving octreotide due to additive effects.
Sotalol: (Major) Diuretics should be used cautiously with sotalol and should be accompanied by close monitoring of electrolyte balance because hypokalemia and hypomagnesemia have been associated with an increased risk of proarrhythmia.
Tolterodine: (Minor) Diuretics can increase urinary frequency, which may aggravate bladder symptoms.
Triamcinolone: (Moderate) The potassium-wasting effects of corticosteroid therapy can be exacerbated by concomitant administration of other potassium-depleting drugs such as diuretics. Serum potassium levels should be monitored in patients receiving these drugs concomitantly.
Vasopressin, ADH: (Minor) Systemic urea can potentiate the antidiuretic effect of vasopressin, ADH when both drugs are used concurrently. Dosage adjustments may be required.

Aluvea/Carmol/Cerovel/DermacinRx Urea/DERMASORB XM Complete/Gordons Urea/Keralac/Keratol/Nutraplus/Rea Lo/Remeven/RYNODERM/U-Kera/Ultralytic-2/URALISS/Uramaxin/Urea/Ureacin/Ureacin-20/Uredeb/URE-K/Uremez-40/Utopic/Vanamide/Xurea/X-VIATE Topical Cream: 10%, 20%, 22%, 35%, 37.5%, 39%, 39.5%, 40%, 41%, 45%, 47%, 50%
BP-50% Urea/Kerol/RE Urea 50/Urea Topical Emulsion: 50%
BP-K50/Kerol/Latrix/Urea Topical Susp: 50%
Carmol Topical Shampoo: 10%
Carmol/CEM-Urea/Cerovel/Keratol/Uramaxin/Uramaxin GT/Urea/X-VIATE Topical Gel: 40%, 45%
Carmol/Cerovel/Keratol/Nutraplus/RE Urea 40/Rea Lo/Ultra Mide 25/Uramaxin/Urea/Ureacin/Ureacin-10/X-VIATE Topical Lotion: 10%, 25%, 40%, 45%
Epimide-50/Urea Topical Paste: 50%
Hydro 35/Hydro 40/Umecta/Uramaxin/Urea Topical Foam: 20%, 35%, 40%
Keralac Nailstik/Urea Topical Sol: 50%
Urea/Ure-Na Oral Pwd F/Recon: 15g

2 applications/day topically; doses up to 180 g/day PO have been used.

2 applications/day topically; doses up to 180 g/day PO have been used.

2 applications/day topically; doses up to 2 g/kg/day PO have been used.

2 applications/day topically; doses up to 2 g/kg/day PO have been used.

Doses up to 2 g/kg/day PO have been used; safety and efficacy have not been established for the topical formulations.

Safety and efficacy have not been established.

Topically, urea promotes the uptake of water by the stratum corneum by allowing it to have a high water-binding capacity. This promotes hydration in dry skin and a mild keratolytic action in hyperkeratotic skin.
 
When used systemically, urea is an osmotic diuretic agent. Urea creates an osmotic gradient across the blood-brain barrier that promotes water flow out of the brain. As the urea gradient across the blood-brain barrier is diminished, it is replaced by an increase in serum sodium concentration that prevents plasma water from reentering the brain. This osmotic effect will persist as long as a gradient exists between the tissues and the blood; as urea diffuses into the tissues, the effect is diminished. Administration of large doses of urea will increase the osmotic pressure of the glomerular filtrate, inhibit the reabsorption of water and solutes in the renal tubule, and induce diuresis.

Urea is used topically and orally. Specific pharmacokinetic parameters for topical application are not available.

Urea is hydrophilic and does not readily permeate artificial lipid bilayers. Urea enters the intracellular space rapidly (in less than 1 hour) throughout the body. Because urea penetrates into the CNS only about one-tenth as quickly as into muscle, a significant intravascular to CNS urea gradient occurs (during 4 to 10 hours). Urea is excreted in the urine, and with normal renal function, all of the administered dose is excreted within approximately 12 hours. Urea leads to a rapid and significant increase in serum sodium concentrations (approximately 7 mEq/L in 48 hours).

Most topical formulations of urea are classified as either FDA pregnancy category B or C. The topical suspension and solution are classified as pregnancy risk B; while the topical paste, shampoo, and nail lacquer are in category C. Depending on the manufacturer, the cream, lotion, emulsion, foam, and gel formulations can be either B or C. Urea topical ointment is not included in the pregnancy category rating. It is not known if topical administration of urea can cause fetal harm when administered to a pregnant woman. Urea should only be administered during pregnancy if clearly needed.

It is not known if urea is excreted in human milk. According to the manufacturer, caution should be exercised when urea is administered to a nursing woman. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.